Modified: trunk/include/linux/kgdb.h (6686 => 6687)
--- trunk/include/linux/kgdb.h 2009-06-12 13:08:53 UTC (rev 6686)
+++ trunk/include/linux/kgdb.h 2009-06-12 13:55:33 UTC (rev 6687)
@@ -204,6 +204,19 @@
*/
extern void kgdb_roundup_cpus(unsigned long flags);
+/**
+ * kgdb_roundup_cpu - Get spcific CPU into a holding pattern
+ * @cpu: Specific cpu id
+ * @flags: Current IRQ state
+ *
+ * On SMP systems, we need to switch cpu from current active one to
+ * the other passive one. This get current active CPU into a known state
+ * in kgdb_wait().
+ *
+ * On non-SMP systems, this is not called.
+ */
+extern void kgdb_roundup_cpu(int cpu, unsigned long flags);
+
/* Optional functions. */
extern int kgdb_validate_break_address(unsigned long addr);
extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
Modified: trunk/kernel/kgdb.c (6686 => 6687)
--- trunk/kernel/kgdb.c 2009-06-12 13:08:53 UTC (rev 6686)
+++ trunk/kernel/kgdb.c 2009-06-12 13:55:33 UTC (rev 6687)
@@ -565,6 +565,7 @@
{
unsigned long flags;
int cpu;
+ struct task_struct *thread;
local_irq_save(flags);
cpu = raw_smp_processor_id();
@@ -577,10 +578,33 @@
smp_wmb();
atomic_set(&cpu_in_kgdb[cpu], 1);
+ kgdb_disable_hw_debug(regs);
+
/* Wait till primary CPU is done with debugging */
while (atomic_read(&passive_cpu_wait[cpu]))
cpu_relax();
+#ifdef __ARCH_SYNC_CORE_ICACHE
+ resync_core_icache();
+#endif
+#ifdef __ARCH_SYNC_CORE_DCACHE
+ resync_core_dcache();
+#endif
+
+ /* Trap into kgdb as the active CPU if gdb asks to switch. */
+ thread = getthread(regs, -cpu - 2);
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ kgdb_contthread && kgdb_contthread == current) {
+ kgdb_breakpoint();
+
+ kgdb_info[cpu].debuggerinfo = NULL;
+ kgdb_info[cpu].task = NULL;
+
+ clocksource_touch_watchdog();
+ local_irq_restore(flags);
+ return;
+ }
+
kgdb_info[cpu].debuggerinfo = NULL;
kgdb_info[cpu].task = NULL;
@@ -1066,13 +1090,16 @@
sprintf(tmpstr, "shadowCPU%d",
(int)(-ks->threadid - 2));
kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
+
+ if (arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP)
+ ks->thr_query = 1;
}
break;
}
}
/* Handle the 'H' task query packets */
-static void gdb_cmd_task(struct kgdb_state *ks)
+static int gdb_cmd_task(struct kgdb_state *ks)
{
struct task_struct *thread;
char *ptr;
@@ -1089,6 +1116,15 @@
kgdb_usethread = thread;
ks->kgdb_usethreadid = ks->threadid;
strcpy(remcom_out_buffer, "OK");
+#ifdef CONFIG_SMP
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ !ks->thr_query && ks->kgdb_usethreadid < -1 &&
+ - ks->kgdb_usethreadid - 2 != raw_smp_processor_id()) {
+ kgdb_roundup_cpu(raw_smp_processor_id(), 0);
+ kgdb_contthread = kgdb_usethread;
+ return 1;
+ }
+#endif
break;
case 'c':
ptr = &remcom_in_buffer[2];
@@ -1102,10 +1138,27 @@
break;
}
kgdb_contthread = thread;
+#ifdef CONFIG_SMP
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ thread != current) {
+ int cpu;
+ for_each_online_cpu(cpu) {
+ if (thread == kgdb_info[cpu].task) {
+ kgdb_roundup_cpu(
+ raw_smp_processor_id(),
+ 0);
+ ks->kgdb_usethreadid = -cpu-2;
+ return 1;
+ }
+ }
+ }
+#endif
}
strcpy(remcom_out_buffer, "OK");
break;
}
+
+ return 0;
}
/* Handle the 'T' thread query packets */
@@ -1114,6 +1167,9 @@
char *ptr = &remcom_in_buffer[1];
struct task_struct *thread;
+ if (arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP)
+ ks->thr_query = 0;
+
kgdb_hex2long(&ptr, &ks->threadid);
thread = getthread(ks->linux_regs, ks->threadid);
if (thread)
@@ -1223,7 +1279,12 @@
/* Clear the out buffer. */
memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
- if (kgdb_connected) {
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) && kgdb_contthread) {
+ remcom_out_buffer[0] = 'O';
+ remcom_out_buffer[1] = 'K';
+ remcom_out_buffer[2] = 0;
+ put_packet(remcom_out_buffer);
+ } else if (kgdb_connected) {
unsigned char thref[8];
char *ptr;
@@ -1238,6 +1299,7 @@
put_packet(remcom_out_buffer);
}
+ kgdb_contthread = current;
kgdb_usethread = kgdb_info[ks->cpu].task;
ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
ks->pass_exception = 0;
@@ -1284,7 +1346,8 @@
gdb_cmd_query(ks);
break;
case 'H': /* task related */
- gdb_cmd_task(ks);
+ if (gdb_cmd_task(ks))
+ goto kgdb_exit;
break;
case 'T': /* Query thread status */
gdb_cmd_thread(ks);
@@ -1324,6 +1387,7 @@
if (error >= 0 || remcom_in_buffer[0] == 'D' ||
remcom_in_buffer[0] == 'k') {
error = 0;
+ kgdb_contthread = NULL;
goto kgdb_exit;
}
@@ -1464,11 +1528,14 @@
* Get the passive CPU lock which will hold all the non-primary
* CPU in a spin state while the debugger is active
*/
- if (!kgdb_single_step) {
+ if (!kgdb_single_step && !kgdb_contthread) {
for (i = 0; i < NR_CPUS; i++)
atomic_set(&passive_cpu_wait[i], 1);
}
+ if (kgdb_contthread)
+ atomic_set(&passive_cpu_wait[raw_smp_processor_id()], 1);
+
/*
* spin_lock code is good enough as a barrier so we don't
* need one here:
@@ -1477,7 +1544,7 @@
#ifdef CONFIG_SMP
/* Signal the other CPUs to enter kgdb_wait() */
- if ((!kgdb_single_step) && kgdb_do_roundup)
+ if ((!kgdb_single_step && !kgdb_contthread) && kgdb_do_roundup)
kgdb_roundup_cpus(flags);
#endif
@@ -1496,7 +1563,6 @@
kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
kgdb_deactivate_sw_breakpoints();
kgdb_single_step = 0;
- kgdb_contthread = current;
exception_level = 0;
/* Talk to debugger with gdbserial protocol */
@@ -1510,7 +1576,14 @@
kgdb_info[ks->cpu].task = NULL;
atomic_set(&cpu_in_kgdb[ks->cpu], 0);
- if (!kgdb_single_step) {
+#ifdef CONFIG_SMP
+ i = -(ks->kgdb_usethreadid + 2);
+ if ((arch_kgdb_ops.flags & KGDB_THR_PROC_SWAP) &&
+ kgdb_contthread && i != cpu) {
+ atomic_set(&passive_cpu_wait[i], 0);
+ }
+#endif
+ if (!kgdb_single_step && !kgdb_contthread) {
for (i = NR_CPUS-1; i >= 0; i--)
atomic_set(&passive_cpu_wait[i], 0);
/*
@@ -1536,9 +1609,9 @@
int kgdb_nmicallback(int cpu, void *regs)
{
#ifdef CONFIG_SMP
- if (!atomic_read(&cpu_in_kgdb[cpu]) &&
+ if (!atomic_read(&cpu_in_kgdb[cpu]) && (kgdb_contthread ||
atomic_read(&kgdb_active) != cpu &&
- atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
+ atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)]))) {
kgdb_wait((struct pt_regs *)regs);
return 0;
}
